移动互联网时代互联网公司平台型经营

介绍了移动互联网已经成为当前信息市场上快速增长的新领域，分析了当今全球成功的互联网公司都是平台型公司的经验和应具备的基本要素，提出了打造成功的平台型公司重在运营创新的建议.     

戈尔推出新一代螺纹型呼吸器

在2011国际电子生产设备贸易博览会上,戈尔公司(W.L.Gore & Associates,Inc.)介绍了新一代螺纹型GORE防水防尘透气产品。在通信领域,各种户外设备因内外压力不平衡而造成设备损坏,戈尔公司的螺纹型呼吸器可以彻底避免这     

UHF高性能硅结型场效应管——国产NU310型N沟结型场效应管

硅N沟结型场效应晶体管在VHF/UHF频段应用,在性能、价格以及稳定可靠性方面均具有很多优点.美国MOTOROLA公司及SILICONIX等公司生产的U310型和BF256型等N沟结型场效应管,都具有良好的高频性能.近年来,这类结型场效应管均已国产化,为VHF/UHF频段的放大、混频以及振荡的应用,提供了方便条件.本文介绍的就是国产NU310型(相当国外U310型)结型场效应管的主要性能及一些电路应用.     

海尔将放弃“中国造”主攻营销市场萎缩利润下滑只能断臂自救

海尔要变了,而且威许是该公司历史上最重要的一次产业转型. 近日,海尔集团CEO张瑞敏称,海尔正计划剥离大部分产品的生产业务以降 低成本,并在为消费者的服务和对市场趋势的反廊方面加快步伐,力求将海尔从制造型转变为营销型公司.     

AWA公司VRB-51D型全向信标设备的一种故障分析

AWA公司的VRB-51D型全向信标设备是民航通信中比较关键的一类设备,此项设备一旦发生故障问题,就会产生参数告警等类型的缺陷,直接影响了全向信标设备的运行效果.本文主要以AWA公司的VRB-51D型全向信标设备为研究对象,分析此项设备的一种故障.     

ZTP135S-R型传感器在体温计中的应用

红外体温计采用红外温度传感器测量体温,利用GE公司的ZTP135S-R型红外热电堆温度传感器实现对温度信号的非接触测量.详细介绍了ZTP135S-R型传感器的工作原理和性能.它与自带ADC的mega16型8位单片机相连,共同实现体温计的功能.     

无序的市场,有序的布局——访PerkinElmer公司大中华区销售总监陈晴

1937年4月19日,两个美国人珀金·理查德和埃尔默·查理斯创立了PerkinElmer公司. 1944年,PerkinElmer公司成功推出世界上第一台商用红外分光光度计-12型开始,这奠定了PerkinElmker公司在分析仪器市场70年的繁荣基础.如今,PerkinElmer公司已经是分析仪器界新技术和完善产品的代名词,位列全球三大品牌之一.     

国外通信保密机厂商及其产品介绍(二)

Hewlett-Packard公司德康分部该公司的德康分部是美国较早从事商业性电话保密机的厂商之一。1959年就开始出售简式电话保密机。到1970年为止,在历年的电子购卖者手册中,都有它的销售广告。1972年前后,公司本部着手研究计算机数据存贮用的数据保密机。先后发表了有关的文献与专利。德康分部的产品主要有:105E型便携式语言倒频保密机;214型和215型无线电话保密机。 105E型保密机有如下几项特点:1.体积小,能放在一般的公文包或手提包中。2.重量轻,总共不足0.76公斤。3.电路简单,仅用了十多只晶体管。4.机内自备3伏电源,可连续工作100     

电视机适于1080p级的技术陆续问世电路集成度的提高促使更多新厂家入行

HDTV的主要动向表现在两个方面:提高画面质量和降低价格. 高画面质量产品的代表,是1080p级HDTV产品,尤其是面向大屏幕市场的1080p级像素型背投电视.例如,精工-爱普生公司采用其最新液晶显示屏技术"D5"的背投电视样机,D5的上一代技术D4也适用于1080p级,富士通-将军公司已经推出采用D4技术的前向投影型电视,但是,本次展示了采用D5技术的背投电视.日本胜利公司展出的适用于1080p的背投电视,采用了该公司的LCoS(硅上液晶)D-ILA技术.     

光学多道谱仪和CCD组合系统的效率曲线标定

介绍了光学多道谱仪的工作原理,采用OMA150谱仪与卤素钨灯耦合作为单色光源,对Acton公司生产的OMA750型谱仪效率进行了标定,获得了OMA750型谱仪在300 g/mm、600 g/mm、1200 g/mm三个不同光栅下的效率曲线;对PI公司生产的TEK512×512型CCD和PID1100×330型CCD的谱响应进行了标定,获得了200～1100 nm波长范围内的谱响应曲线.     

Electrothermal simulations in punchthrough and nonpunchthroughIGBT's

The performance of 1200 V punchthrough (PT) and nonpunchthrough (NPT) insulated gate bipolar transistors (IGBT's) is studied in detail under unclamped inductive switching (UIS) and short circuit (SC) conditions. The need for a good physics based simulator to carry out a reliability study is pointed out in the paper. Using such a finite element-based device and circuit simulator it is shown that NPT-IGBT's show a much better performance than PT-IGBTs under UIS condition. It is also shown that an NPT device has a better short circuit withstanding capability than a PT device due to the structural differences between the two devices. As there is a huge power loss within the device during these operating conditions, device self-heating is expected to have a significant impact on device characteristics. Electrothermal simulations are used to study device self-heating and it is shown that it significantly influences device performance under SC operation whereas self-heating influences the UIS performance of only the PT device with little effect on the NPT device. The study is validated by an experimental study of short circuit failure of PT IGBTs     

虚拟设备在嵌入式LINUX系统中的使用

在Linux系统中，系统是把设备映射为一个特殊的设备文件，用户程序可以象对其它文件一样对此设备文件进行操作。我们可以根据这一点，构造一个不连接任何硬件的设备文件，即虚拟设备。利用这个设备，我们可以把一系列的底层操作转化为应用层操作，以减低上层工作量。     

Demonstration and properties of a planar heterojunction bipolartransistor with lateral current flow

The authors present fabrication techniques and device performance for a novel transistor structure, the lateral heterojunction bipolar transistor. The lateral heterojunctions are formed by impurity-induced disordering of a GaAs base layer sandwiched between two AlGaAs layers. These transistor structures exhibit current gains of 14 for base widths of 0.74 μm. Transistor action in this device occurs parallel to the surface of the device structure. The active base region of the structure is completely submerged, resulting in a reduction of surface recombination as a mechanism for gain reduction in the device. Impurity-induced disordering is used to widen the bandgap of the alloy in the emitter and collector, resulting in an improvement of the emitter injection efficiency. Since the device is based entirely on a surface diffusion process, the device is completely planar and has no steps involving etching of the III-V alloy material. These advantages lead this device to be considered as a candidate for optoelectronic integration applications. The transistor device functions as a buried heterostructure laser, with a threshold current as low as 6 mA for a 1.4-μm stripe     

High-mobility GeSi PMOS on SIMOX

A new p-channel GeSi-SIMOX device is presented. The device consists of a Si/Ge_0.3Si_0.7/Si channel, which is grown pseudomorphically on a SIMOX substrate. Due to reduced vertical electric field and band bending at the surface of a GeSi-SIMOX device, hole confinement in the buried channel is improved over that of a GeSi-bulk device. Experimentally, the effective channel mobility of this device is found to be 90% higher than that of an identically processed conventional SIMOX device     

基于SON的MOSFET器件及其工艺方法研究

超薄体SOI器件能够有效抑制短沟道效应,业界认为在纳米器件时代它有可能取代传统体硅器件。但SOI器件的全局化埋氧层特性会使其产生自加热效应,严重时会导致器件开态电流下降、漏电流增加,从而导致器件可靠性降低。具有局部空洞层或介质层的SON器件及其制备方法已成为纳米器件时代的一个研究热点。阐述了SON器件的基本概念,比较了SON器件和传统体硅器件的电学特性。对SON器件的工艺制备方法进行了全面描述,包括早期的SON器件制备方法、基于MSTS的SON制备方法、气体注入SON制备方法,以及完全自对准SON器件制备方法。详细描述了准自对准气体注入SON器件和完全自对准SON器件制备方法的工艺流程。     

A traveling-wave high electron mobility transistor

A traveling-wave high electron mobility transistor (THEMT) is proposed. The device is unique in that it includes an integral distributed load resistor and uses a HEMT as the active device. A rigorous analysis of the device is carried out, using a small-signal equivalent circuit model for an incremental section of the device. Losses and reflected waves are not neglected, as has been done in other work. Treating the device as a four-port network, closed-form expressions for S-parameters are derived. Theoretical calculations, using equivalent circuit parameter values for a HEMT reported in the literature, show that the proposed device is capable of exponential increase in gain with device width. Power gain of more than 10 dB at 50 GHz and remarkably flat response in the frequency range 10-100 GHz are shown to be achievable for a 1-mm-wide device     

带激光辅助照明的微光夜视仪

介绍了一种新型微光夜视仪的性能指标、组成及工作原理．该夜视仪最大的优点在于自身携带激光光源,因此克服了传统夜视仪在全黑天气下无法工作的缺点．在全黑天气下,该夜视仪的视距为1．7km,而且用该夜视仪监视目标时,具有运动检测功能,即对运动目标能发出报警信息。     

纳米器件的发展动态

介绍了纳米CMOS器件、纳米电子器件和量子器件的发展动态,提出以信息载体来分类纳米器件的方式。在纳米CMOS器件方面,主要介绍近半年来65nm工艺及器件的最新动态;在纳米电子器件方面,主要介绍共振隧穿器件(RTD)的动态;在量子器件方面,主要介绍量子器件和半导体自旋器件的概况。     

Performance of field-induced directional coupler switches

Switching in a GaAs field-induced, three-waveguide straight directional coupler is studied theoretically. This device can be tuned externally by changing the voltage across the waveguides. Because of this tunability, the device has some very attractive features as a switching element. The performance change due to variations in the device parameters such as length, waveguide separation, waveguide width, and wavelength of operation is numerically computed. The effect of material absorption, input and output coupling, and asymmetric excitation are included in the performance evaluation. For a device length of 1400 μm, a crosstalk of -34 dB and a power transfer efficiency of -2 dB is predicted, while for the same device size a two-guide directional coupler is predicted a crosstalk of -13.4 dB. The device has a 400 nm voltage tunable bandwidth with a maximum crosstalk penalty of 3 dB     

微波晶体管测试夹具技术的研究

微波晶体管是无线通信、雷达等电子系统中的关键部分。由于其高频特性以及一般非50Ω特性阻抗,准确评估其性能有较大的难度。晶体管大都为不同形式的表面贴装或表面安装器件,而目前微波测试系统基本上都是同轴传输系统,因此,就需要通过测试夹具完成对测试器件固定、馈电以及信号同轴传输转微带传输的功能。微波器件测试是保证器件质量和发展的关键手段,夹具制作技术对测试结果影响巨大,对微波晶体管测试夹具制作进行了研究,并提出了解决方案。